git.oblomov.eu Git - linux-2.6/blob - drivers/kvm/mmu.c

   1 /*
   2  * Kernel-based Virtual Machine driver for Linux
   3  *
   4  * This module enables machines with Intel VT-x extensions to run virtual
   5  * machines without emulation or binary translation.
   6  *
   7  * MMU support
   8  *
   9  * Copyright (C) 2006 Qumranet, Inc.
  10  *
  11  * Authors:
  12  *   Yaniv Kamay  <yaniv@qumranet.com>
  13  *   Avi Kivity   <avi@qumranet.com>
  14  *
  15  * This work is licensed under the terms of the GNU GPL, version 2.  See
  16  * the COPYING file in the top-level directory.
  17  *
  18  */
  19
  20 #include "vmx.h"
  21 #include "kvm.h"
  22
  23 #include <linux/types.h>
  24 #include <linux/string.h>
  25 #include <linux/mm.h>
  26 #include <linux/highmem.h>
  27 #include <linux/module.h>
  28
  29 #include <asm/page.h>
  30 #include <asm/cmpxchg.h>
  31
  32 #undef MMU_DEBUG
  33
  34 #undef AUDIT
  35
  36 #ifdef AUDIT
  37 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg);
  38 #else
  39 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg) {}
  40 #endif
  41
  42 #ifdef MMU_DEBUG
  43
  44 #define pgprintk(x...) do { if (dbg) printk(x); } while (0)
  45 #define rmap_printk(x...) do { if (dbg) printk(x); } while (0)
  46
  47 #else
  48
  49 #define pgprintk(x...) do { } while (0)
  50 #define rmap_printk(x...) do { } while (0)
  51
  52 #endif
  53
  54 #if defined(MMU_DEBUG) || defined(AUDIT)
  55 static int dbg = 1;
  56 #endif
  57
  58 #ifndef MMU_DEBUG
  59 #define ASSERT(x) do { } while (0)
  60 #else
  61 #define ASSERT(x)                                                       \
  62         if (!(x)) {                                                     \
  63                 printk(KERN_WARNING "assertion failed %s:%d: %s\n",     \
  64                        __FILE__, __LINE__, #x);                         \
  65         }
  66 #endif
  67
  68 #define PT64_PT_BITS 9
  69 #define PT64_ENT_PER_PAGE (1 << PT64_PT_BITS)
  70 #define PT32_PT_BITS 10
  71 #define PT32_ENT_PER_PAGE (1 << PT32_PT_BITS)
  72
  73 #define PT_WRITABLE_SHIFT 1
  74
  75 #define PT_PRESENT_MASK (1ULL << 0)
  76 #define PT_WRITABLE_MASK (1ULL << PT_WRITABLE_SHIFT)
  77 #define PT_USER_MASK (1ULL << 2)
  78 #define PT_PWT_MASK (1ULL << 3)
  79 #define PT_PCD_MASK (1ULL << 4)
  80 #define PT_ACCESSED_MASK (1ULL << 5)
  81 #define PT_DIRTY_MASK (1ULL << 6)
  82 #define PT_PAGE_SIZE_MASK (1ULL << 7)
  83 #define PT_PAT_MASK (1ULL << 7)
  84 #define PT_GLOBAL_MASK (1ULL << 8)
  85 #define PT64_NX_MASK (1ULL << 63)
  86
  87 #define PT_PAT_SHIFT 7
  88 #define PT_DIR_PAT_SHIFT 12
  89 #define PT_DIR_PAT_MASK (1ULL << PT_DIR_PAT_SHIFT)
  90
  91 #define PT32_DIR_PSE36_SIZE 4
  92 #define PT32_DIR_PSE36_SHIFT 13
  93 #define PT32_DIR_PSE36_MASK (((1ULL << PT32_DIR_PSE36_SIZE) - 1) << PT32_DIR_PSE36_SHIFT)
  94
  95
  96 #define PT_FIRST_AVAIL_BITS_SHIFT 9
  97 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
  98
  99 #define PT_SHADOW_IO_MARK (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
 100
 101 #define VALID_PAGE(x) ((x) != INVALID_PAGE)
 102
 103 #define PT64_LEVEL_BITS 9
 104
 105 #define PT64_LEVEL_SHIFT(level) \
 106                 ( PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS )
 107
 108 #define PT64_LEVEL_MASK(level) \
 109                 (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level))
 110
 111 #define PT64_INDEX(address, level)\
 112         (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
 113
 114
 115 #define PT32_LEVEL_BITS 10
 116
 117 #define PT32_LEVEL_SHIFT(level) \
 118                 ( PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS )
 119
 120 #define PT32_LEVEL_MASK(level) \
 121                 (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level))
 122
 123 #define PT32_INDEX(address, level)\
 124         (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
 125
 126
 127 #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
 128 #define PT64_DIR_BASE_ADDR_MASK \
 129         (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
 130
 131 #define PT32_BASE_ADDR_MASK PAGE_MASK
 132 #define PT32_DIR_BASE_ADDR_MASK \
 133         (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
 134
 135
 136 #define PFERR_PRESENT_MASK (1U << 0)
 137 #define PFERR_WRITE_MASK (1U << 1)
 138 #define PFERR_USER_MASK (1U << 2)
 139 #define PFERR_FETCH_MASK (1U << 4)
 140
 141 #define PT64_ROOT_LEVEL 4
 142 #define PT32_ROOT_LEVEL 2
 143 #define PT32E_ROOT_LEVEL 3
 144
 145 #define PT_DIRECTORY_LEVEL 2
 146 #define PT_PAGE_TABLE_LEVEL 1
 147
 148 #define RMAP_EXT 4
 149
 150 struct kvm_rmap_desc {
 151         u64 *shadow_ptes[RMAP_EXT];
 152         struct kvm_rmap_desc *more;
 153 };
 154
 155 static struct kmem_cache *pte_chain_cache;
 156 static struct kmem_cache *rmap_desc_cache;
 157 static struct kmem_cache *mmu_page_cache;
 158 static struct kmem_cache *mmu_page_header_cache;
 159
 160 static int is_write_protection(struct kvm_vcpu *vcpu)
 161 {
 162         return vcpu->cr0 & CR0_WP_MASK;
 163 }
 164
 165 static int is_cpuid_PSE36(void)
 166 {
 167         return 1;
 168 }
 169
 170 static int is_nx(struct kvm_vcpu *vcpu)
 171 {
 172         return vcpu->shadow_efer & EFER_NX;
 173 }
 174
 175 static int is_present_pte(unsigned long pte)
 176 {
 177         return pte & PT_PRESENT_MASK;
 178 }
 179
 180 static int is_writeble_pte(unsigned long pte)
 181 {
 182         return pte & PT_WRITABLE_MASK;
 183 }
 184
 185 static int is_io_pte(unsigned long pte)
 186 {
 187         return pte & PT_SHADOW_IO_MARK;
 188 }
 189
 190 static int is_rmap_pte(u64 pte)
 191 {
 192         return (pte & (PT_WRITABLE_MASK | PT_PRESENT_MASK))
 193                 == (PT_WRITABLE_MASK | PT_PRESENT_MASK);
 194 }
 195
 196 static void set_shadow_pte(u64 *sptep, u64 spte)
 197 {
 198 #ifdef CONFIG_X86_64
 199         set_64bit((unsigned long *)sptep, spte);
 200 #else
 201         set_64bit((unsigned long long *)sptep, spte);
 202 #endif
 203 }
 204
 205 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
 206                                   struct kmem_cache *base_cache, int min,
 207                                   gfp_t gfp_flags)
 208 {
 209         void *obj;
 210
 211         if (cache->nobjs >= min)
 212                 return 0;
 213         while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
 214                 obj = kmem_cache_zalloc(base_cache, gfp_flags);
 215                 if (!obj)
 216                         return -ENOMEM;
 217                 cache->objects[cache->nobjs++] = obj;
 218         }
 219         return 0;
 220 }
 221
 222 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
 223 {
 224         while (mc->nobjs)
 225                 kfree(mc->objects[--mc->nobjs]);
 226 }
 227
 228 static int __mmu_topup_memory_caches(struct kvm_vcpu *vcpu, gfp_t gfp_flags)
 229 {
 230         int r;
 231
 232         r = mmu_topup_memory_cache(&vcpu->mmu_pte_chain_cache,
 233                                    pte_chain_cache, 4, gfp_flags);
 234         if (r)
 235                 goto out;
 236         r = mmu_topup_memory_cache(&vcpu->mmu_rmap_desc_cache,
 237                                    rmap_desc_cache, 1, gfp_flags);
 238         if (r)
 239                 goto out;
 240         r = mmu_topup_memory_cache(&vcpu->mmu_page_cache,
 241                                    mmu_page_cache, 4, gfp_flags);
 242         if (r)
 243                 goto out;
 244         r = mmu_topup_memory_cache(&vcpu->mmu_page_header_cache,
 245                                    mmu_page_header_cache, 4, gfp_flags);
 246 out:
 247         return r;
 248 }
 249
 250 static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
 251 {
 252         int r;
 253
 254         r = __mmu_topup_memory_caches(vcpu, GFP_NOWAIT);
 255         if (r < 0) {
 256                 spin_unlock(&vcpu->kvm->lock);
 257                 kvm_arch_ops->vcpu_put(vcpu);
 258                 r = __mmu_topup_memory_caches(vcpu, GFP_KERNEL);
 259                 kvm_arch_ops->vcpu_load(vcpu);
 260                 spin_lock(&vcpu->kvm->lock);
 261         }
 262         return r;
 263 }
 264
 265 static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
 266 {
 267         mmu_free_memory_cache(&vcpu->mmu_pte_chain_cache);
 268         mmu_free_memory_cache(&vcpu->mmu_rmap_desc_cache);
 269         mmu_free_memory_cache(&vcpu->mmu_page_cache);
 270         mmu_free_memory_cache(&vcpu->mmu_page_header_cache);
 271 }
 272
 273 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc,
 274                                     size_t size)
 275 {
 276         void *p;
 277
 278         BUG_ON(!mc->nobjs);
 279         p = mc->objects[--mc->nobjs];
 280         memset(p, 0, size);
 281         return p;
 282 }
 283
 284 static struct kvm_pte_chain *mmu_alloc_pte_chain(struct kvm_vcpu *vcpu)
 285 {
 286         return mmu_memory_cache_alloc(&vcpu->mmu_pte_chain_cache,
 287                                       sizeof(struct kvm_pte_chain));
 288 }
 289
 290 static void mmu_free_pte_chain(struct kvm_pte_chain *pc)
 291 {
 292         kfree(pc);
 293 }
 294
 295 static struct kvm_rmap_desc *mmu_alloc_rmap_desc(struct kvm_vcpu *vcpu)
 296 {
 297         return mmu_memory_cache_alloc(&vcpu->mmu_rmap_desc_cache,
 298                                       sizeof(struct kvm_rmap_desc));
 299 }
 300
 301 static void mmu_free_rmap_desc(struct kvm_rmap_desc *rd)
 302 {
 303         kfree(rd);
 304 }
 305
 306 /*
 307  * Reverse mapping data structures:
 308  *
 309  * If page->private bit zero is zero, then page->private points to the
 310  * shadow page table entry that points to page_address(page).
 311  *
 312  * If page->private bit zero is one, (then page->private & ~1) points
 313  * to a struct kvm_rmap_desc containing more mappings.
 314  */
 315 static void rmap_add(struct kvm_vcpu *vcpu, u64 *spte)
 316 {
 317         struct page *page;
 318         struct kvm_rmap_desc *desc;
 319         int i;
 320
 321         if (!is_rmap_pte(*spte))
 322                 return;
 323         page = pfn_to_page((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT);
 324         if (!page_private(page)) {
 325                 rmap_printk("rmap_add: %p %llx 0->1\n", spte, *spte);
 326                 set_page_private(page,(unsigned long)spte);
 327         } else if (!(page_private(page) & 1)) {
 328                 rmap_printk("rmap_add: %p %llx 1->many\n", spte, *spte);
 329                 desc = mmu_alloc_rmap_desc(vcpu);
 330                 desc->shadow_ptes[0] = (u64 *)page_private(page);
 331                 desc->shadow_ptes[1] = spte;
 332                 set_page_private(page,(unsigned long)desc | 1);
 333         } else {
 334                 rmap_printk("rmap_add: %p %llx many->many\n", spte, *spte);
 335                 desc = (struct kvm_rmap_desc *)(page_private(page) & ~1ul);
 336                 while (desc->shadow_ptes[RMAP_EXT-1] && desc->more)
 337                         desc = desc->more;
 338                 if (desc->shadow_ptes[RMAP_EXT-1]) {
 339                         desc->more = mmu_alloc_rmap_desc(vcpu);
 340                         desc = desc->more;
 341                 }
 342                 for (i = 0; desc->shadow_ptes[i]; ++i)
 343                         ;
 344                 desc->shadow_ptes[i] = spte;
 345         }
 346 }
 347
 348 static void rmap_desc_remove_entry(struct page *page,
 349                                    struct kvm_rmap_desc *desc,
 350                                    int i,
 351                                    struct kvm_rmap_desc *prev_desc)
 352 {
 353         int j;
 354
 355         for (j = RMAP_EXT - 1; !desc->shadow_ptes[j] && j > i; --j)
 356                 ;
 357         desc->shadow_ptes[i] = desc->shadow_ptes[j];
 358         desc->shadow_ptes[j] = NULL;
 359         if (j != 0)
 360                 return;
 361         if (!prev_desc && !desc->more)
 362                 set_page_private(page,(unsigned long)desc->shadow_ptes[0]);
 363         else
 364                 if (prev_desc)
 365                         prev_desc->more = desc->more;
 366                 else
 367                         set_page_private(page,(unsigned long)desc->more | 1);
 368         mmu_free_rmap_desc(desc);
 369 }
 370
 371 static void rmap_remove(u64 *spte)
 372 {
 373         struct page *page;
 374         struct kvm_rmap_desc *desc;
 375         struct kvm_rmap_desc *prev_desc;
 376         int i;
 377
 378         if (!is_rmap_pte(*spte))
 379                 return;
 380         page = pfn_to_page((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT);
 381         if (!page_private(page)) {
 382                 printk(KERN_ERR "rmap_remove: %p %llx 0->BUG\n", spte, *spte);
 383                 BUG();
 384         } else if (!(page_private(page) & 1)) {
 385                 rmap_printk("rmap_remove:  %p %llx 1->0\n", spte, *spte);
 386                 if ((u64 *)page_private(page) != spte) {
 387                         printk(KERN_ERR "rmap_remove:  %p %llx 1->BUG\n",
 388                                spte, *spte);
 389                         BUG();
 390                 }
 391                 set_page_private(page,0);
 392         } else {
 393                 rmap_printk("rmap_remove:  %p %llx many->many\n", spte, *spte);
 394                 desc = (struct kvm_rmap_desc *)(page_private(page) & ~1ul);
 395                 prev_desc = NULL;
 396                 while (desc) {
 397                         for (i = 0; i < RMAP_EXT && desc->shadow_ptes[i]; ++i)
 398                                 if (desc->shadow_ptes[i] == spte) {
 399                                         rmap_desc_remove_entry(page,
 400                                                                desc, i,
 401                                                                prev_desc);
 402                                         return;
 403                                 }
 404                         prev_desc = desc;
 405                         desc = desc->more;
 406                 }
 407                 BUG();
 408         }
 409 }
 410
 411 static void rmap_write_protect(struct kvm_vcpu *vcpu, u64 gfn)
 412 {
 413         struct kvm *kvm = vcpu->kvm;
 414         struct page *page;
 415         struct kvm_rmap_desc *desc;
 416         u64 *spte;
 417
 418         page = gfn_to_page(kvm, gfn);
 419         BUG_ON(!page);
 420
 421         while (page_private(page)) {
 422                 if (!(page_private(page) & 1))
 423                         spte = (u64 *)page_private(page);
 424                 else {
 425                         desc = (struct kvm_rmap_desc *)(page_private(page) & ~1ul);
 426                         spte = desc->shadow_ptes[0];
 427                 }
 428                 BUG_ON(!spte);
 429                 BUG_ON((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT
 430                        != page_to_pfn(page));
 431                 BUG_ON(!(*spte & PT_PRESENT_MASK));
 432                 BUG_ON(!(*spte & PT_WRITABLE_MASK));
 433                 rmap_printk("rmap_write_protect: spte %p %llx\n", spte, *spte);
 434                 rmap_remove(spte);
 435                 set_shadow_pte(spte, *spte & ~PT_WRITABLE_MASK);
 436                 kvm_flush_remote_tlbs(vcpu->kvm);
 437         }
 438 }
 439
 440 #ifdef MMU_DEBUG
 441 static int is_empty_shadow_page(u64 *spt)
 442 {
 443         u64 *pos;
 444         u64 *end;
 445
 446         for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++)
 447                 if (*pos != 0) {
 448                         printk(KERN_ERR "%s: %p %llx\n", __FUNCTION__,
 449                                pos, *pos);
 450                         return 0;
 451                 }
 452         return 1;
 453 }
 454 #endif
 455
 456 static void kvm_mmu_free_page(struct kvm *kvm,
 457                               struct kvm_mmu_page *page_head)
 458 {
 459         ASSERT(is_empty_shadow_page(page_head->spt));
 460         list_del(&page_head->link);
 461         kfree(page_head->spt);
 462         kfree(page_head);
 463         ++kvm->n_free_mmu_pages;
 464 }
 465
 466 static unsigned kvm_page_table_hashfn(gfn_t gfn)
 467 {
 468         return gfn;
 469 }
 470
 471 static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
 472                                                u64 *parent_pte)
 473 {
 474         struct kvm_mmu_page *page;
 475
 476         if (!vcpu->kvm->n_free_mmu_pages)
 477                 return NULL;
 478
 479         page = mmu_memory_cache_alloc(&vcpu->mmu_page_header_cache,
 480                                       sizeof *page);
 481         page->spt = mmu_memory_cache_alloc(&vcpu->mmu_page_cache, PAGE_SIZE);
 482         set_page_private(virt_to_page(page->spt), (unsigned long)page);
 483         list_add(&page->link, &vcpu->kvm->active_mmu_pages);
 484         ASSERT(is_empty_shadow_page(page->spt));
 485         page->slot_bitmap = 0;
 486         page->multimapped = 0;
 487         page->parent_pte = parent_pte;
 488         --vcpu->kvm->n_free_mmu_pages;
 489         return page;
 490 }
 491
 492 static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu,
 493                                     struct kvm_mmu_page *page, u64 *parent_pte)
 494 {
 495         struct kvm_pte_chain *pte_chain;
 496         struct hlist_node *node;
 497         int i;
 498
 499         if (!parent_pte)
 500                 return;
 501         if (!page->multimapped) {
 502                 u64 *old = page->parent_pte;
 503
 504                 if (!old) {
 505                         page->parent_pte = parent_pte;
 506                         return;
 507                 }
 508                 page->multimapped = 1;
 509                 pte_chain = mmu_alloc_pte_chain(vcpu);
 510                 INIT_HLIST_HEAD(&page->parent_ptes);
 511                 hlist_add_head(&pte_chain->link, &page->parent_ptes);
 512                 pte_chain->parent_ptes[0] = old;
 513         }
 514         hlist_for_each_entry(pte_chain, node, &page->parent_ptes, link) {
 515                 if (pte_chain->parent_ptes[NR_PTE_CHAIN_ENTRIES-1])
 516                         continue;
 517                 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i)
 518                         if (!pte_chain->parent_ptes[i]) {
 519                                 pte_chain->parent_ptes[i] = parent_pte;
 520                                 return;
 521                         }
 522         }
 523         pte_chain = mmu_alloc_pte_chain(vcpu);
 524         BUG_ON(!pte_chain);
 525         hlist_add_head(&pte_chain->link, &page->parent_ptes);
 526         pte_chain->parent_ptes[0] = parent_pte;
 527 }
 528
 529 static void mmu_page_remove_parent_pte(struct kvm_mmu_page *page,
 530                                        u64 *parent_pte)
 531 {
 532         struct kvm_pte_chain *pte_chain;
 533         struct hlist_node *node;
 534         int i;
 535
 536         if (!page->multimapped) {
 537                 BUG_ON(page->parent_pte != parent_pte);
 538                 page->parent_pte = NULL;
 539                 return;
 540         }
 541         hlist_for_each_entry(pte_chain, node, &page->parent_ptes, link)
 542                 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
 543                         if (!pte_chain->parent_ptes[i])
 544                                 break;
 545                         if (pte_chain->parent_ptes[i] != parent_pte)
 546                                 continue;
 547                         while (i + 1 < NR_PTE_CHAIN_ENTRIES
 548                                 && pte_chain->parent_ptes[i + 1]) {
 549                                 pte_chain->parent_ptes[i]
 550                                         = pte_chain->parent_ptes[i + 1];
 551                                 ++i;
 552                         }
 553                         pte_chain->parent_ptes[i] = NULL;
 554                         if (i == 0) {
 555                                 hlist_del(&pte_chain->link);
 556                                 mmu_free_pte_chain(pte_chain);
 557                                 if (hlist_empty(&page->parent_ptes)) {
 558                                         page->multimapped = 0;
 559                                         page->parent_pte = NULL;
 560                                 }
 561                         }
 562                         return;
 563                 }
 564         BUG();
 565 }
 566
 567 static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm_vcpu *vcpu,
 568                                                 gfn_t gfn)
 569 {
 570         unsigned index;
 571         struct hlist_head *bucket;
 572         struct kvm_mmu_page *page;
 573         struct hlist_node *node;
 574
 575         pgprintk("%s: looking for gfn %lx\n", __FUNCTION__, gfn);
 576         index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
 577         bucket = &vcpu->kvm->mmu_page_hash[index];
 578         hlist_for_each_entry(page, node, bucket, hash_link)
 579                 if (page->gfn == gfn && !page->role.metaphysical) {
 580                         pgprintk("%s: found role %x\n",
 581                                  __FUNCTION__, page->role.word);
 582                         return page;
 583                 }
 584         return NULL;
 585 }
 586
 587 static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
 588                                              gfn_t gfn,
 589                                              gva_t gaddr,
 590                                              unsigned level,
 591                                              int metaphysical,
 592                                              unsigned hugepage_access,
 593                                              u64 *parent_pte)
 594 {
 595         union kvm_mmu_page_role role;
 596         unsigned index;
 597         unsigned quadrant;
 598         struct hlist_head *bucket;
 599         struct kvm_mmu_page *page;
 600         struct hlist_node *node;
 601
 602         role.word = 0;
 603         role.glevels = vcpu->mmu.root_level;
 604         role.level = level;
 605         role.metaphysical = metaphysical;
 606         role.hugepage_access = hugepage_access;
 607         if (vcpu->mmu.root_level <= PT32_ROOT_LEVEL) {
 608                 quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level));
 609                 quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
 610                 role.quadrant = quadrant;
 611         }
 612         pgprintk("%s: looking gfn %lx role %x\n", __FUNCTION__,
 613                  gfn, role.word);
 614         index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
 615         bucket = &vcpu->kvm->mmu_page_hash[index];
 616         hlist_for_each_entry(page, node, bucket, hash_link)
 617                 if (page->gfn == gfn && page->role.word == role.word) {
 618                         mmu_page_add_parent_pte(vcpu, page, parent_pte);
 619                         pgprintk("%s: found\n", __FUNCTION__);
 620                         return page;
 621                 }
 622         page = kvm_mmu_alloc_page(vcpu, parent_pte);
 623         if (!page)
 624                 return page;
 625         pgprintk("%s: adding gfn %lx role %x\n", __FUNCTION__, gfn, role.word);
 626         page->gfn = gfn;
 627         page->role = role;
 628         hlist_add_head(&page->hash_link, bucket);
 629         if (!metaphysical)
 630                 rmap_write_protect(vcpu, gfn);
 631         return page;
 632 }
 633
 634 static void kvm_mmu_page_unlink_children(struct kvm *kvm,
 635                                          struct kvm_mmu_page *page)
 636 {
 637         unsigned i;
 638         u64 *pt;
 639         u64 ent;
 640
 641         pt = page->spt;
 642
 643         if (page->role.level == PT_PAGE_TABLE_LEVEL) {
 644                 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
 645                         if (pt[i] & PT_PRESENT_MASK)
 646                                 rmap_remove(&pt[i]);
 647                         pt[i] = 0;
 648                 }
 649                 kvm_flush_remote_tlbs(kvm);
 650                 return;
 651         }
 652
 653         for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
 654                 ent = pt[i];
 655
 656                 pt[i] = 0;
 657                 if (!(ent & PT_PRESENT_MASK))
 658                         continue;
 659                 ent &= PT64_BASE_ADDR_MASK;
 660                 mmu_page_remove_parent_pte(page_header(ent), &pt[i]);
 661         }
 662         kvm_flush_remote_tlbs(kvm);
 663 }
 664
 665 static void kvm_mmu_put_page(struct kvm_mmu_page *page,
 666                              u64 *parent_pte)
 667 {
 668         mmu_page_remove_parent_pte(page, parent_pte);
 669 }
 670
 671 static void kvm_mmu_zap_page(struct kvm *kvm,
 672                              struct kvm_mmu_page *page)
 673 {
 674         u64 *parent_pte;
 675
 676         while (page->multimapped || page->parent_pte) {
 677                 if (!page->multimapped)
 678                         parent_pte = page->parent_pte;
 679                 else {
 680                         struct kvm_pte_chain *chain;
 681
 682                         chain = container_of(page->parent_ptes.first,
 683                                              struct kvm_pte_chain, link);
 684                         parent_pte = chain->parent_ptes[0];
 685                 }
 686                 BUG_ON(!parent_pte);
 687                 kvm_mmu_put_page(page, parent_pte);
 688                 set_shadow_pte(parent_pte, 0);
 689         }
 690         kvm_mmu_page_unlink_children(kvm, page);
 691         if (!page->root_count) {
 692                 hlist_del(&page->hash_link);
 693                 kvm_mmu_free_page(kvm, page);
 694         } else
 695                 list_move(&page->link, &kvm->active_mmu_pages);
 696 }
 697
 698 static int kvm_mmu_unprotect_page(struct kvm_vcpu *vcpu, gfn_t gfn)
 699 {
 700         unsigned index;
 701         struct hlist_head *bucket;
 702         struct kvm_mmu_page *page;
 703         struct hlist_node *node, *n;
 704         int r;
 705
 706         pgprintk("%s: looking for gfn %lx\n", __FUNCTION__, gfn);
 707         r = 0;
 708         index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
 709         bucket = &vcpu->kvm->mmu_page_hash[index];
 710         hlist_for_each_entry_safe(page, node, n, bucket, hash_link)
 711                 if (page->gfn == gfn && !page->role.metaphysical) {
 712                         pgprintk("%s: gfn %lx role %x\n", __FUNCTION__, gfn,
 713                                  page->role.word);
 714                         kvm_mmu_zap_page(vcpu->kvm, page);
 715                         r = 1;
 716                 }
 717         return r;
 718 }
 719
 720 static void mmu_unshadow(struct kvm_vcpu *vcpu, gfn_t gfn)
 721 {
 722         struct kvm_mmu_page *page;
 723
 724         while ((page = kvm_mmu_lookup_page(vcpu, gfn)) != NULL) {
 725                 pgprintk("%s: zap %lx %x\n",
 726                          __FUNCTION__, gfn, page->role.word);
 727                 kvm_mmu_zap_page(vcpu->kvm, page);
 728         }
 729 }
 730
 731 static void page_header_update_slot(struct kvm *kvm, void *pte, gpa_t gpa)
 732 {
 733         int slot = memslot_id(kvm, gfn_to_memslot(kvm, gpa >> PAGE_SHIFT));
 734         struct kvm_mmu_page *page_head = page_header(__pa(pte));
 735
 736         __set_bit(slot, &page_head->slot_bitmap);
 737 }
 738
 739 hpa_t safe_gpa_to_hpa(struct kvm_vcpu *vcpu, gpa_t gpa)
 740 {
 741         hpa_t hpa = gpa_to_hpa(vcpu, gpa);
 742
 743         return is_error_hpa(hpa) ? bad_page_address | (gpa & ~PAGE_MASK): hpa;
 744 }
 745
 746 hpa_t gpa_to_hpa(struct kvm_vcpu *vcpu, gpa_t gpa)
 747 {
 748         struct page *page;
 749
 750         ASSERT((gpa & HPA_ERR_MASK) == 0);
 751         page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
 752         if (!page)
 753                 return gpa | HPA_ERR_MASK;
 754         return ((hpa_t)page_to_pfn(page) << PAGE_SHIFT)
 755                 | (gpa & (PAGE_SIZE-1));
 756 }
 757
 758 hpa_t gva_to_hpa(struct kvm_vcpu *vcpu, gva_t gva)
 759 {
 760         gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, gva);
 761
 762         if (gpa == UNMAPPED_GVA)
 763                 return UNMAPPED_GVA;
 764         return gpa_to_hpa(vcpu, gpa);
 765 }
 766
 767 struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva)
 768 {
 769         gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, gva);
 770
 771         if (gpa == UNMAPPED_GVA)
 772                 return NULL;
 773         return pfn_to_page(gpa_to_hpa(vcpu, gpa) >> PAGE_SHIFT);
 774 }
 775
 776 static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
 777 {
 778 }
 779
 780 static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, hpa_t p)
 781 {
 782         int level = PT32E_ROOT_LEVEL;
 783         hpa_t table_addr = vcpu->mmu.root_hpa;
 784
 785         for (; ; level--) {
 786                 u32 index = PT64_INDEX(v, level);
 787                 u64 *table;
 788                 u64 pte;
 789
 790                 ASSERT(VALID_PAGE(table_addr));
 791                 table = __va(table_addr);
 792
 793                 if (level == 1) {
 794                         pte = table[index];
 795                         if (is_present_pte(pte) && is_writeble_pte(pte))
 796                                 return 0;
 797                         mark_page_dirty(vcpu->kvm, v >> PAGE_SHIFT);
 798                         page_header_update_slot(vcpu->kvm, table, v);
 799                         table[index] = p | PT_PRESENT_MASK | PT_WRITABLE_MASK |
 800                                                                 PT_USER_MASK;
 801                         rmap_add(vcpu, &table[index]);
 802                         return 0;
 803                 }
 804
 805                 if (table[index] == 0) {
 806                         struct kvm_mmu_page *new_table;
 807                         gfn_t pseudo_gfn;
 808
 809                         pseudo_gfn = (v & PT64_DIR_BASE_ADDR_MASK)
 810                                 >> PAGE_SHIFT;
 811                         new_table = kvm_mmu_get_page(vcpu, pseudo_gfn,
 812                                                      v, level - 1,
 813                                                      1, 0, &table[index]);
 814                         if (!new_table) {
 815                                 pgprintk("nonpaging_map: ENOMEM\n");
 816                                 return -ENOMEM;
 817                         }
 818
 819                         table[index] = __pa(new_table->spt) | PT_PRESENT_MASK
 820                                 | PT_WRITABLE_MASK | PT_USER_MASK;
 821                 }
 822                 table_addr = table[index] & PT64_BASE_ADDR_MASK;
 823         }
 824 }
 825
 826 static void mmu_free_roots(struct kvm_vcpu *vcpu)
 827 {
 828         int i;
 829         struct kvm_mmu_page *page;
 830
 831         if (!VALID_PAGE(vcpu->mmu.root_hpa))
 832                 return;
 833 #ifdef CONFIG_X86_64
 834         if (vcpu->mmu.shadow_root_level == PT64_ROOT_LEVEL) {
 835                 hpa_t root = vcpu->mmu.root_hpa;
 836
 837                 page = page_header(root);
 838                 --page->root_count;
 839                 vcpu->mmu.root_hpa = INVALID_PAGE;
 840                 return;
 841         }
 842 #endif
 843         for (i = 0; i < 4; ++i) {
 844                 hpa_t root = vcpu->mmu.pae_root[i];
 845
 846                 if (root) {
 847                         root &= PT64_BASE_ADDR_MASK;
 848                         page = page_header(root);
 849                         --page->root_count;
 850                 }
 851                 vcpu->mmu.pae_root[i] = INVALID_PAGE;
 852         }
 853         vcpu->mmu.root_hpa = INVALID_PAGE;
 854 }
 855
 856 static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
 857 {
 858         int i;
 859         gfn_t root_gfn;
 860         struct kvm_mmu_page *page;
 861
 862         root_gfn = vcpu->cr3 >> PAGE_SHIFT;
 863
 864 #ifdef CONFIG_X86_64
 865         if (vcpu->mmu.shadow_root_level == PT64_ROOT_LEVEL) {
 866                 hpa_t root = vcpu->mmu.root_hpa;
 867
 868                 ASSERT(!VALID_PAGE(root));
 869                 page = kvm_mmu_get_page(vcpu, root_gfn, 0,
 870                                         PT64_ROOT_LEVEL, 0, 0, NULL);
 871                 root = __pa(page->spt);
 872                 ++page->root_count;
 873                 vcpu->mmu.root_hpa = root;
 874                 return;
 875         }
 876 #endif
 877         for (i = 0; i < 4; ++i) {
 878                 hpa_t root = vcpu->mmu.pae_root[i];
 879
 880                 ASSERT(!VALID_PAGE(root));
 881                 if (vcpu->mmu.root_level == PT32E_ROOT_LEVEL) {
 882                         if (!is_present_pte(vcpu->pdptrs[i])) {
 883                                 vcpu->mmu.pae_root[i] = 0;
 884                                 continue;
 885                         }
 886                         root_gfn = vcpu->pdptrs[i] >> PAGE_SHIFT;
 887                 } else if (vcpu->mmu.root_level == 0)
 888                         root_gfn = 0;
 889                 page = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
 890                                         PT32_ROOT_LEVEL, !is_paging(vcpu),
 891                                         0, NULL);
 892                 root = __pa(page->spt);
 893                 ++page->root_count;
 894                 vcpu->mmu.pae_root[i] = root | PT_PRESENT_MASK;
 895         }
 896         vcpu->mmu.root_hpa = __pa(vcpu->mmu.pae_root);
 897 }
 898
 899 static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr)
 900 {
 901         return vaddr;
 902 }
 903
 904 static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
 905                                u32 error_code)
 906 {
 907         gpa_t addr = gva;
 908         hpa_t paddr;
 909         int r;
 910
 911         r = mmu_topup_memory_caches(vcpu);
 912         if (r)
 913                 return r;
 914
 915         ASSERT(vcpu);
 916         ASSERT(VALID_PAGE(vcpu->mmu.root_hpa));
 917
 918
 919         paddr = gpa_to_hpa(vcpu , addr & PT64_BASE_ADDR_MASK);
 920
 921         if (is_error_hpa(paddr))
 922                 return 1;
 923
 924         return nonpaging_map(vcpu, addr & PAGE_MASK, paddr);
 925 }
 926
 927 static void nonpaging_free(struct kvm_vcpu *vcpu)
 928 {
 929         mmu_free_roots(vcpu);
 930 }
 931
 932 static int nonpaging_init_context(struct kvm_vcpu *vcpu)
 933 {
 934         struct kvm_mmu *context = &vcpu->mmu;
 935
 936         context->new_cr3 = nonpaging_new_cr3;
 937         context->page_fault = nonpaging_page_fault;
 938         context->gva_to_gpa = nonpaging_gva_to_gpa;
 939         context->free = nonpaging_free;
 940         context->root_level = 0;
 941         context->shadow_root_level = PT32E_ROOT_LEVEL;
 942         context->root_hpa = INVALID_PAGE;
 943         return 0;
 944 }
 945
 946 static void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu)
 947 {
 948         ++vcpu->stat.tlb_flush;
 949         kvm_arch_ops->tlb_flush(vcpu);
 950 }
 951
 952 static void paging_new_cr3(struct kvm_vcpu *vcpu)
 953 {
 954         pgprintk("%s: cr3 %lx\n", __FUNCTION__, vcpu->cr3);
 955         mmu_free_roots(vcpu);
 956 }
 957
 958 static void inject_page_fault(struct kvm_vcpu *vcpu,
 959                               u64 addr,
 960                               u32 err_code)
 961 {
 962         kvm_arch_ops->inject_page_fault(vcpu, addr, err_code);
 963 }
 964
 965 static void paging_free(struct kvm_vcpu *vcpu)
 966 {
 967         nonpaging_free(vcpu);
 968 }
 969
 970 #define PTTYPE 64
 971 #include "paging_tmpl.h"
 972 #undef PTTYPE
 973
 974 #define PTTYPE 32
 975 #include "paging_tmpl.h"
 976 #undef PTTYPE
 977
 978 static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level)
 979 {
 980         struct kvm_mmu *context = &vcpu->mmu;
 981
 982         ASSERT(is_pae(vcpu));
 983         context->new_cr3 = paging_new_cr3;
 984         context->page_fault = paging64_page_fault;
 985         context->gva_to_gpa = paging64_gva_to_gpa;
 986         context->free = paging_free;
 987         context->root_level = level;
 988         context->shadow_root_level = level;
 989         context->root_hpa = INVALID_PAGE;
 990         return 0;
 991 }
 992
 993 static int paging64_init_context(struct kvm_vcpu *vcpu)
 994 {
 995         return paging64_init_context_common(vcpu, PT64_ROOT_LEVEL);
 996 }
 997
 998 static int paging32_init_context(struct kvm_vcpu *vcpu)
 999 {
1000         struct kvm_mmu *context = &vcpu->mmu;
1001
1002         context->new_cr3 = paging_new_cr3;
1003         context->page_fault = paging32_page_fault;
1004         context->gva_to_gpa = paging32_gva_to_gpa;
1005         context->free = paging_free;
1006         context->root_level = PT32_ROOT_LEVEL;
1007         context->shadow_root_level = PT32E_ROOT_LEVEL;
1008         context->root_hpa = INVALID_PAGE;
1009         return 0;
1010 }
1011
1012 static int paging32E_init_context(struct kvm_vcpu *vcpu)
1013 {
1014         return paging64_init_context_common(vcpu, PT32E_ROOT_LEVEL);
1015 }
1016
1017 static int init_kvm_mmu(struct kvm_vcpu *vcpu)
1018 {
1019         ASSERT(vcpu);
1020         ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa));
1021
1022         if (!is_paging(vcpu))
1023                 return nonpaging_init_context(vcpu);
1024         else if (is_long_mode(vcpu))
1025                 return paging64_init_context(vcpu);
1026         else if (is_pae(vcpu))
1027                 return paging32E_init_context(vcpu);
1028         else
1029                 return paging32_init_context(vcpu);
1030 }
1031
1032 static void destroy_kvm_mmu(struct kvm_vcpu *vcpu)
1033 {
1034         ASSERT(vcpu);
1035         if (VALID_PAGE(vcpu->mmu.root_hpa)) {
1036                 vcpu->mmu.free(vcpu);
1037                 vcpu->mmu.root_hpa = INVALID_PAGE;
1038         }
1039 }
1040
1041 int kvm_mmu_reset_context(struct kvm_vcpu *vcpu)
1042 {
1043         destroy_kvm_mmu(vcpu);
1044         return init_kvm_mmu(vcpu);
1045 }
1046
1047 int kvm_mmu_load(struct kvm_vcpu *vcpu)
1048 {
1049         int r;
1050
1051         spin_lock(&vcpu->kvm->lock);
1052         r = mmu_topup_memory_caches(vcpu);
1053         if (r)
1054                 goto out;
1055         mmu_alloc_roots(vcpu);
1056         kvm_arch_ops->set_cr3(vcpu, vcpu->mmu.root_hpa);
1057         kvm_mmu_flush_tlb(vcpu);
1058 out:
1059         spin_unlock(&vcpu->kvm->lock);
1060         return r;
1061 }
1062 EXPORT_SYMBOL_GPL(kvm_mmu_load);
1063
1064 void kvm_mmu_unload(struct kvm_vcpu *vcpu)
1065 {
1066         mmu_free_roots(vcpu);
1067 }
1068
1069 static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu,
1070                                   struct kvm_mmu_page *page,
1071                                   u64 *spte)
1072 {
1073         u64 pte;
1074         struct kvm_mmu_page *child;
1075
1076         pte = *spte;
1077         if (is_present_pte(pte)) {
1078                 if (page->role.level == PT_PAGE_TABLE_LEVEL)
1079                         rmap_remove(spte);
1080                 else {
1081                         child = page_header(pte & PT64_BASE_ADDR_MASK);
1082                         mmu_page_remove_parent_pte(child, spte);
1083                 }
1084         }
1085         *spte = 0;
1086         kvm_flush_remote_tlbs(vcpu->kvm);
1087 }
1088
1089 static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu,
1090                                   struct kvm_mmu_page *page,
1091                                   u64 *spte,
1092                                   const void *new, int bytes)
1093 {
1094         if (page->role.level != PT_PAGE_TABLE_LEVEL)
1095                 return;
1096
1097         if (page->role.glevels == PT32_ROOT_LEVEL)
1098                 paging32_update_pte(vcpu, page, spte, new, bytes);
1099         else
1100                 paging64_update_pte(vcpu, page, spte, new, bytes);
1101 }
1102
1103 void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
1104                        const u8 *old, const u8 *new, int bytes)
1105 {
1106         gfn_t gfn = gpa >> PAGE_SHIFT;
1107         struct kvm_mmu_page *page;
1108         struct hlist_node *node, *n;
1109         struct hlist_head *bucket;
1110         unsigned index;
1111         u64 *spte;
1112         unsigned offset = offset_in_page(gpa);
1113         unsigned pte_size;
1114         unsigned page_offset;
1115         unsigned misaligned;
1116         unsigned quadrant;
1117         int level;
1118         int flooded = 0;
1119         int npte;
1120
1121         pgprintk("%s: gpa %llx bytes %d\n", __FUNCTION__, gpa, bytes);
1122         if (gfn == vcpu->last_pt_write_gfn) {
1123                 ++vcpu->last_pt_write_count;
1124                 if (vcpu->last_pt_write_count >= 3)
1125                         flooded = 1;
1126         } else {
1127                 vcpu->last_pt_write_gfn = gfn;
1128                 vcpu->last_pt_write_count = 1;
1129         }
1130         index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
1131         bucket = &vcpu->kvm->mmu_page_hash[index];
1132         hlist_for_each_entry_safe(page, node, n, bucket, hash_link) {
1133                 if (page->gfn != gfn || page->role.metaphysical)
1134                         continue;
1135                 pte_size = page->role.glevels == PT32_ROOT_LEVEL ? 4 : 8;
1136                 misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1);
1137                 misaligned |= bytes < 4;
1138                 if (misaligned || flooded) {
1139                         /*
1140                          * Misaligned accesses are too much trouble to fix
1141                          * up; also, they usually indicate a page is not used
1142                          * as a page table.
1143                          *
1144                          * If we're seeing too many writes to a page,
1145                          * it may no longer be a page table, or we may be
1146                          * forking, in which case it is better to unmap the
1147                          * page.
1148                          */
1149                         pgprintk("misaligned: gpa %llx bytes %d role %x\n",
1150                                  gpa, bytes, page->role.word);
1151                         kvm_mmu_zap_page(vcpu->kvm, page);
1152                         continue;
1153                 }
1154                 page_offset = offset;
1155                 level = page->role.level;
1156                 npte = 1;
1157                 if (page->role.glevels == PT32_ROOT_LEVEL) {
1158                         page_offset <<= 1;      /* 32->64 */
1159                         /*
1160                          * A 32-bit pde maps 4MB while the shadow pdes map
1161                          * only 2MB.  So we need to double the offset again
1162                          * and zap two pdes instead of one.
1163                          */
1164                         if (level == PT32_ROOT_LEVEL) {
1165                                 page_offset &= ~7; /* kill rounding error */
1166                                 page_offset <<= 1;
1167                                 npte = 2;
1168                         }
1169                         quadrant = page_offset >> PAGE_SHIFT;
1170                         page_offset &= ~PAGE_MASK;
1171                         if (quadrant != page->role.quadrant)
1172                                 continue;
1173                 }
1174                 spte = &page->spt[page_offset / sizeof(*spte)];
1175                 while (npte--) {
1176                         mmu_pte_write_zap_pte(vcpu, page, spte);
1177                         mmu_pte_write_new_pte(vcpu, page, spte, new, bytes);
1178                         ++spte;
1179                 }
1180         }
1181 }
1182
1183 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
1184 {
1185         gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, gva);
1186
1187         return kvm_mmu_unprotect_page(vcpu, gpa >> PAGE_SHIFT);
1188 }
1189
1190 void kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
1191 {
1192         while (vcpu->kvm->n_free_mmu_pages < KVM_REFILL_PAGES) {
1193                 struct kvm_mmu_page *page;
1194
1195                 page = container_of(vcpu->kvm->active_mmu_pages.prev,
1196                                     struct kvm_mmu_page, link);
1197                 kvm_mmu_zap_page(vcpu->kvm, page);
1198         }
1199 }
1200 EXPORT_SYMBOL_GPL(kvm_mmu_free_some_pages);
1201
1202 static void free_mmu_pages(struct kvm_vcpu *vcpu)
1203 {
1204         struct kvm_mmu_page *page;
1205
1206         while (!list_empty(&vcpu->kvm->active_mmu_pages)) {
1207                 page = container_of(vcpu->kvm->active_mmu_pages.next,
1208                                     struct kvm_mmu_page, link);
1209                 kvm_mmu_zap_page(vcpu->kvm, page);
1210         }
1211         free_page((unsigned long)vcpu->mmu.pae_root);
1212 }
1213
1214 static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
1215 {
1216         struct page *page;
1217         int i;
1218
1219         ASSERT(vcpu);
1220
1221         vcpu->kvm->n_free_mmu_pages = KVM_NUM_MMU_PAGES;
1222
1223         /*
1224          * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
1225          * Therefore we need to allocate shadow page tables in the first
1226          * 4GB of memory, which happens to fit the DMA32 zone.
1227          */
1228         page = alloc_page(GFP_KERNEL | __GFP_DMA32);
1229         if (!page)
1230                 goto error_1;
1231         vcpu->mmu.pae_root = page_address(page);
1232         for (i = 0; i < 4; ++i)
1233                 vcpu->mmu.pae_root[i] = INVALID_PAGE;
1234
1235         return 0;
1236
1237 error_1:
1238         free_mmu_pages(vcpu);
1239         return -ENOMEM;
1240 }
1241
1242 int kvm_mmu_create(struct kvm_vcpu *vcpu)
1243 {
1244         ASSERT(vcpu);
1245         ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa));
1246
1247         return alloc_mmu_pages(vcpu);
1248 }
1249
1250 int kvm_mmu_setup(struct kvm_vcpu *vcpu)
1251 {
1252         ASSERT(vcpu);
1253         ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa));
1254
1255         return init_kvm_mmu(vcpu);
1256 }
1257
1258 void kvm_mmu_destroy(struct kvm_vcpu *vcpu)
1259 {
1260         ASSERT(vcpu);
1261
1262         destroy_kvm_mmu(vcpu);
1263         free_mmu_pages(vcpu);
1264         mmu_free_memory_caches(vcpu);
1265 }
1266
1267 void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
1268 {
1269         struct kvm_mmu_page *page;
1270
1271         list_for_each_entry(page, &kvm->active_mmu_pages, link) {
1272                 int i;
1273                 u64 *pt;
1274
1275                 if (!test_bit(slot, &page->slot_bitmap))
1276                         continue;
1277
1278                 pt = page->spt;
1279                 for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
1280                         /* avoid RMW */
1281                         if (pt[i] & PT_WRITABLE_MASK) {
1282                                 rmap_remove(&pt[i]);
1283                                 pt[i] &= ~PT_WRITABLE_MASK;
1284                         }
1285         }
1286 }
1287
1288 void kvm_mmu_zap_all(struct kvm *kvm)
1289 {
1290         struct kvm_mmu_page *page, *node;
1291
1292         list_for_each_entry_safe(page, node, &kvm->active_mmu_pages, link)
1293                 kvm_mmu_zap_page(kvm, page);
1294
1295         kvm_flush_remote_tlbs(kvm);
1296 }
1297
1298 void kvm_mmu_module_exit(void)
1299 {
1300         if (pte_chain_cache)
1301                 kmem_cache_destroy(pte_chain_cache);
1302         if (rmap_desc_cache)
1303                 kmem_cache_destroy(rmap_desc_cache);
1304         if (mmu_page_cache)
1305                 kmem_cache_destroy(mmu_page_cache);
1306         if (mmu_page_header_cache)
1307                 kmem_cache_destroy(mmu_page_header_cache);
1308 }
1309
1310 int kvm_mmu_module_init(void)
1311 {
1312         pte_chain_cache = kmem_cache_create("kvm_pte_chain",
1313                                             sizeof(struct kvm_pte_chain),
1314                                             0, 0, NULL);
1315         if (!pte_chain_cache)
1316                 goto nomem;
1317         rmap_desc_cache = kmem_cache_create("kvm_rmap_desc",
1318                                             sizeof(struct kvm_rmap_desc),
1319                                             0, 0, NULL);
1320         if (!rmap_desc_cache)
1321                 goto nomem;
1322
1323         mmu_page_cache = kmem_cache_create("kvm_mmu_page",
1324                                            PAGE_SIZE,
1325                                            PAGE_SIZE, 0, NULL);
1326         if (!mmu_page_cache)
1327                 goto nomem;
1328
1329         mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header",
1330                                                   sizeof(struct kvm_mmu_page),
1331                                                   0, 0, NULL);
1332         if (!mmu_page_header_cache)
1333                 goto nomem;
1334
1335         return 0;
1336
1337 nomem:
1338         kvm_mmu_module_exit();
1339         return -ENOMEM;
1340 }
1341
1342 #ifdef AUDIT
1343
1344 static const char *audit_msg;
1345
1346 static gva_t canonicalize(gva_t gva)
1347 {
1348 #ifdef CONFIG_X86_64
1349         gva = (long long)(gva << 16) >> 16;
1350 #endif
1351         return gva;
1352 }
1353
1354 static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
1355                                 gva_t va, int level)
1356 {
1357         u64 *pt = __va(page_pte & PT64_BASE_ADDR_MASK);
1358         int i;
1359         gva_t va_delta = 1ul << (PAGE_SHIFT + 9 * (level - 1));
1360
1361         for (i = 0; i < PT64_ENT_PER_PAGE; ++i, va += va_delta) {
1362                 u64 ent = pt[i];
1363
1364                 if (!(ent & PT_PRESENT_MASK))
1365                         continue;
1366
1367                 va = canonicalize(va);
1368                 if (level > 1)
1369                         audit_mappings_page(vcpu, ent, va, level - 1);
1370                 else {
1371                         gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, va);
1372                         hpa_t hpa = gpa_to_hpa(vcpu, gpa);
1373
1374                         if ((ent & PT_PRESENT_MASK)
1375                             && (ent & PT64_BASE_ADDR_MASK) != hpa)
1376                                 printk(KERN_ERR "audit error: (%s) levels %d"
1377                                        " gva %lx gpa %llx hpa %llx ent %llx\n",
1378                                        audit_msg, vcpu->mmu.root_level,
1379                                        va, gpa, hpa, ent);
1380                 }
1381         }
1382 }
1383
1384 static void audit_mappings(struct kvm_vcpu *vcpu)
1385 {
1386         unsigned i;
1387
1388         if (vcpu->mmu.root_level == 4)
1389                 audit_mappings_page(vcpu, vcpu->mmu.root_hpa, 0, 4);
1390         else
1391                 for (i = 0; i < 4; ++i)
1392                         if (vcpu->mmu.pae_root[i] & PT_PRESENT_MASK)
1393                                 audit_mappings_page(vcpu,
1394                                                     vcpu->mmu.pae_root[i],
1395                                                     i << 30,
1396                                                     2);
1397 }
1398
1399 static int count_rmaps(struct kvm_vcpu *vcpu)
1400 {
1401         int nmaps = 0;
1402         int i, j, k;
1403
1404         for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
1405                 struct kvm_memory_slot *m = &vcpu->kvm->memslots[i];
1406                 struct kvm_rmap_desc *d;
1407
1408                 for (j = 0; j < m->npages; ++j) {
1409                         struct page *page = m->phys_mem[j];
1410
1411                         if (!page->private)
1412                                 continue;
1413                         if (!(page->private & 1)) {
1414                                 ++nmaps;
1415                                 continue;
1416                         }
1417                         d = (struct kvm_rmap_desc *)(page->private & ~1ul);
1418                         while (d) {
1419                                 for (k = 0; k < RMAP_EXT; ++k)
1420                                         if (d->shadow_ptes[k])
1421                                                 ++nmaps;
1422                                         else
1423                                                 break;
1424                                 d = d->more;
1425                         }
1426                 }
1427         }
1428         return nmaps;
1429 }
1430
1431 static int count_writable_mappings(struct kvm_vcpu *vcpu)
1432 {
1433         int nmaps = 0;
1434         struct kvm_mmu_page *page;
1435         int i;
1436
1437         list_for_each_entry(page, &vcpu->kvm->active_mmu_pages, link) {
1438                 u64 *pt = page->spt;
1439
1440                 if (page->role.level != PT_PAGE_TABLE_LEVEL)
1441                         continue;
1442
1443                 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
1444                         u64 ent = pt[i];
1445
1446                         if (!(ent & PT_PRESENT_MASK))
1447                                 continue;
1448                         if (!(ent & PT_WRITABLE_MASK))
1449                                 continue;
1450                         ++nmaps;
1451                 }
1452         }
1453         return nmaps;
1454 }
1455
1456 static void audit_rmap(struct kvm_vcpu *vcpu)
1457 {
1458         int n_rmap = count_rmaps(vcpu);
1459         int n_actual = count_writable_mappings(vcpu);
1460
1461         if (n_rmap != n_actual)
1462                 printk(KERN_ERR "%s: (%s) rmap %d actual %d\n",
1463                        __FUNCTION__, audit_msg, n_rmap, n_actual);
1464 }
1465
1466 static void audit_write_protection(struct kvm_vcpu *vcpu)
1467 {
1468         struct kvm_mmu_page *page;
1469
1470         list_for_each_entry(page, &vcpu->kvm->active_mmu_pages, link) {
1471                 hfn_t hfn;
1472                 struct page *pg;
1473
1474                 if (page->role.metaphysical)
1475                         continue;
1476
1477                 hfn = gpa_to_hpa(vcpu, (gpa_t)page->gfn << PAGE_SHIFT)
1478                         >> PAGE_SHIFT;
1479                 pg = pfn_to_page(hfn);
1480                 if (pg->private)
1481                         printk(KERN_ERR "%s: (%s) shadow page has writable"
1482                                " mappings: gfn %lx role %x\n",
1483                                __FUNCTION__, audit_msg, page->gfn,
1484                                page->role.word);
1485         }
1486 }
1487
1488 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg)
1489 {
1490         int olddbg = dbg;
1491
1492         dbg = 0;
1493         audit_msg = msg;
1494         audit_rmap(vcpu);
1495         audit_write_protection(vcpu);
1496         audit_mappings(vcpu);
1497         dbg = olddbg;
1498 }
1499
1500 #endif